As a method for loading particles on a surface of a thermoplastic resin fiber,
a method in which particles are fixed to the surface of the thermoplastic resin fiber with an adhesive (a binder) (Patent Literature 1), a method in which particles heated to a temperature which is higher that the melting point of a thermoplastic resin fiber are contacted to the thermoplastic resin fiber to fuse the particles to the surface of the thermoplastic resin fiber (Patent Literature 2), etc., are known.
Meanwhile, as a method for adsorbing child particles onto mother particles, a method in which the surfaces of the mother particles and child particles are coated respectively with polyelectrolytes that are electrostatically charged to electric charges opposite to each other (cationic polymer or anionic polymer), thereby allowing the child particles to be adsorbed on the mother particles by electrostatic interaction (Patent Literature 3).